Air cooled heat sinks are known in the art for dissipating heat from electronic components. One variety of such heat sinks comprises a block of heat conductive metal (e.g. aluminum) on one side of which heat generating electronic components are connected, and on an opposite side of which are provided a plurality of rectangular fins which create a large heat exchange surface for dissipating heat to the ambient air.
U.S. Pat. Nos. 4,884,331 and 4,879,891 (both assigned to Thermaloy Incorporated) show such a prior art heatsink designs. These patents teach the ratio of height of the fins to the width of the grooves therebetween may be increased by sawing the grooves with an appropriate sawing device to provide gang sawing of all of the grooves simultaneously.
U.S. Pat. No. 5,406,698 (Lipinski) discloses a method and apparatus for fabricating heat sinks wherein a block of aluminum is extruded with a plurality of grooves and a plurality of fins having bell-bottom shaped foot portions are swaged into the grooves.
Wire fin and pin fin heat sinks are also known in the art in accordance with which serpentine wires, square fins and cylindrical pins, replace the rectangular fins discussed above. The increased air circulation around these heat exchange surfaces results in greater heat dissipating efficiency than prior art rectangular fin heat sinks.
A method for manufacturing a multiple pin heat sink is set forth in U.S. Pat. No. 5,499,450 (Jacoby) in which a dye member is utilised for forming the pin elements.
U.S. Pat. No. 5,351,748 (Dagan) also discloses a pin fin heat sink comprising a base with an array of tubular pins extending outwardly therefrom. The pins are engaged with apertures recessed into the base by means of an expansion member (e.g. ball bearing) positioned within a tubular portion of each pin, wherein the expansion member causes the wall of the pin to deform outwardly to clampingly engage the pin within the aperture.
It is also known in the art to create pin-fin style heat sinks using fins cut or stamped to form a plurality of pin-like fingers.
For example, U.S. Pat. No., 5,421,406 (Furusawa et al) discloses fabrication of "comb-like" pin fins for use in a heat sink. The fins are stamped or blanked out from a metal sheet.
U.S. Pat. No. 5,419,051 (Ozeki) also teaches "comb-like" pin fins for use in a heat sink. According to this patent, the fins are stamped out to form slits.
U.S. Pat. No. 5,381,859 (Minakami et al) also discloses fabrication of a plurality of fins which are stamped out to form slits which may be rotated relative to adjacent heat sink fin elements so as to form a three dimensional matrix of pin fins.